/*
 * Copyright (C) 2011 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the
 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;

import java.io.Serializable;
import javax.annotation.CheckForNull;

/**
 * A mutable value of type {@code int}, for multisets to use in tracking counts of values.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class Count implements Serializable
{
    private int value;

    Count(int value)
    {
        this.value = value;
    }

    public int get()
    {
        return value;
    }

    public void add(int delta)
    {
        value += delta;
    }

    public int addAndGet(int delta)
    {
        return value += delta;
    }

    public void set(int newValue)
    {
        value = newValue;
    }

    public int getAndSet(int newValue)
    {
        int result = value;
        value = newValue;
        return result;
    }

    @Override
    public int hashCode()
    {
        return value;
    }

    @Override
    public boolean equals(@CheckForNull Object obj)
    {
        return obj instanceof Count && ((Count) obj).value == value;
    }

    @Override
    public String toString()
    {
        return Integer.toString(value);
    }
}
